Process for manufacturing sulphur dyestuffs



Patented May 20, I

I UNITED STATES PATENT OFFICE enone 'xnmscnnn, or rnanxronr-on rnn-mam,AND 'nnmarcn BITTER, or

DIETEBHEII-ON-THE-m, GERMAN Y, ASSIGNOR TO GENERAL ANILINE WORKS, INC.,01' NEW YORK, N. Y., A CORPORATION OF DELAWARE PROCESS FOR MANUFACTURINGSULPHUR .DYEBTUIIS Io Drawing. Application fled June 28,

Our invention relates to a new and advantageous improvement in theprocess for producing sulphur dyestuffs which improvementconsists inusing hydroaromatic hydroxy- 5 compounds as solvents in "the heatingprocess with polysulfides. Suitable solvents of this kind are forinstance cyclohexanol and its homologues, tetralol, decalol and similarcompounds.

It is a surprising fact that polysulfides are easily soluble inhydroaromatic hydroxycompounds without affecting them, so that thelatter can be nearly completely recovered from the reaction mass withoutbeing dehydrogenated.

The especial technical effect of our improvedprocess consists incarrying out the sulphurlzation process in a. homogeneous melt atrelatively high temperatures. The success of the reaction is favorablyinfluenced by the further fact that the components to be sulphurized atthe elevated temperatures applied are mostly easily soluble in thesolvents used and that therefore their reactivity to- .wardspolysulfides is essentially increased. Owing-to these facts according toour improved process the sulphurization effected in a substantially.shorter time than it -Was hitherto possible. As a consequence of thisreduction of time very'pure and very soluble dyestuffs are produced inan e ellent yield 'without the formation of less soluble byproductswhich are high extension of phurizing' for a longer time in the usualmanner.

Our improved able for the oduetion of the important class of sulphurdyestuffs derived from indophenols and their leucocompounds it being ofspecial technical importance to produce this class of sulphur dye-stuffsin a really p'ure state.

When carrying out our process practically the reaction mass is worked upin the usual manner. The solvent may be recovered by steam distillationor distillationin vacuo and the inorganic salts maybe removed'from theremaining residue as usually. In many cases when the yestufis directlyseparate from the fusion mass, the dyestuffs may be isolated byparticular conditions nor til the generally formed .by a. toosulphurization whep/sulherto process is particularly suitgreat purity1928, serial No. 288,529, and in Germany lnly 11, 1927.

direct filtration and the solvent may be directly used for furtherfusion operations.

In order to further illustrate our invention the following examplesaregiven, the parts being by weight and all temperatures in centigradedegrees. understood, that we are not limited to the to the specificproducts mentioned therein.

Example 1 v parts of sodium sulfide of 60%, 150 parts of sulphur and 500parts of methylcyclohexanol are heated at about while stirring'until themass is wholly dissolved. Thereafter 100 parts of 3- (4'-hydroxyphenyl)-amino-carbazole of the probable ormulag: 1

are introduced'and the mixture is heated at first while using a coolingdistilling tube *unwater contained in the fusion mass is distilled off,then heating is continued while using for 2-3 hours, whereby the formeddyestuif slowly separates from the fusion mass, In'

order to isolate it the mass is poured on cold water and thecyclohexanol is distilled ofi by'means of steam. Then the dyestufi isfil tered off and in order to remove the excess of sulphur theprecipitate is treated either in a moist state with a solution of sodiumsulfide or when 'dry with a solvent asfcarbon disul fide.

The dyestufl' thus obtained generally shows the properties of thedyestufi prepared We wish it however to be a reflux condenser at about160 according to the U. S. Patent No. 956,348.

But our product surpasses the said one by its and coloring power as alsoby its ability tobe easily vatted. y

In the same manner one may proceed when starting from the indophenolprepared fronf nitrosophenol and ethylcarbazole. Furthermore themethyl-cyclohexanol may be replaced by similar compounds as for instancec clohexanol itself or ac-tetrahydro-naph- Example 2 I 46 arts of sodiumsulfide of 60%, 37 parts of su hur and 200 parts of cyclohexanol areheated at about 100 while stirring. Thereafter 12 parts of crystallizedcopper sulfate and 40 parts of the leuco-indophenol prepared v ple 1.

from l-para-tolyl-amino-napththalene-8-sulfonic acid andaraFamino-phenol and corresponding proba 1y to the formula CaO-NQMnO-QHare introduced. The mixture is heated at about 165 for about one to twohours. Then the dyestufi is isolated as described in Exam- It isidentical with the product preared accordin to the U. S. Patent No.76,885 and is istinguished by an excellent purity and coloring power.

Example 3 200 parts of sodium sulfide of 250 parts of sulphur and1500parts of methylcyclohexanol are heated to 100120. Then 200 parts of4-amino-3-methyl-4'-hydroxydiphenyl-amine of the formula:

no-O-nn-Q-Nm I are introduced while stirring and the mixture is heatedto 160-165 for about 2 hours. The

mass is worked up as described in Example 1. The dyestufi thus producedis identical with the dyestufi prepared according to the U. S. PatentNo. 709,151, surpassing it by-a greater purity.

Eamnple 4 46 arts of sodium sulfide of 60%, 61 parts of s phur and 200parts of. methyl-cyclohexanol are heated f r a short time to about Then50 arts of 4-phenylamino-4- hydroxy-dipheny -amine of the formula:

pounds includes the 'indophenols and their leuco-compounds.

We claim:

1. The process which comprises heating an indophenol compound withpolysulfidcs in the presence of a hydroaromatic hydroxy-compound as asolvent.

' 2. The process which comprises heating an indophenol compound withpolysulfides in the presence of a hydroaromatic hydroxycompound solvent.

3. The process which comprises heating an indophenol compound withpolysulfides in the presence of methyl-cyclohexanol as a solvent. v,

4; The process which comprises heating 3- (4'-hydroxy-phenyl)-amino-carbazole with polysulfides in the presence of ahydroaromatichydroxy-compound of the cyclohexanol series as a solvent. 1

5.The process which co iprises heating 3- (4-hydroxy-phenyl) -aminl-carbazole with of the cyclohexanol series as a polysulfides'in thepresence of methyl-cyclohexanol as a solvent. I

In testimony whereof we a-flix our signatures.

GEORG KALISCHER. HEINRICH BITTER.

are introduced while stirring and the mass v is'heated to about 160for}; hours. Thereafter the mixture. is diluted-with cold water and themethyl-cyclohexanol is distilled ofi by means of steam. Thed yestufiisseparated distillation residue or by I The product is identical to butpurer then the dyestufi pre-

